I have a 1,6 year old son. Today I first put him in "the corner" after counting to three, explaining that this would happen when he doesn´t behave. Then I told him that he should stay there until he was ready to apologise. (He didn´t close the toilet when asked.) He cried and I know that he didn´t understand but I still feel its time to show him somehow that I mean business when no means no. My husband is a programmer and is afraid that our son will hate numbers if we use 1-2-3 as the trigger to "the corner". And we want our son to love numbers. So I need help... what can I use as a definite "Oh no you didn´t" type of phrasing that makes him realize that punishment is on way. This has to give him time to stop...1-2... Thank you for your world of wisdom.
We use the 1.2.3 rule, and I'm a computer programmer, and my oldest son (6 years old) loves math. Just because you use numbers, it doesn't mean they will relate that to math. My now-1st grader loves addition, subtraction, even does simple (6x3 type) multiplication. We have, however, used 1..2..3 since he was little to let him understand that we need his attention NOW. Now my 3 year old doesn't get the 1..2..3 thing at all, so we're having to use something different with him, but with my oldest it works quite well (and the 3-year old is starting to get the idea we're serious when we use it, it's just not quite as good response).
All of that said, if you're still desiring an alternative, perhaps use A..B..C? (although the programmer should also quail at using simple variables, but hey?). Or green... yellow... red? (this may not work depending on favorite colors, etc.). My kids are starting to learn that when I say "I'm very disappointed", they know that they did something wrong, that may work as well, although it's more of a post-event statement as opposed to a get-your-attention statement.
We really tried avoiding 1,2,3 with our son, preferring time outs, but time outs just weren't that effective. So long as 3 reliably results in a consequence he does not like, he generally responds as desired. (For him, he wants to do stuff himself, so the consequence is usually getting picked up or us doing the thing for him.)
We also use 1,2,3 as the count when doing hide and seek and other games, so he's learned that numbers can be a lot of fun. He enjoys counting to ten and then jumping (into pool, off couches, etc.) Counting objects can also be a fun past time.
So, if it is working keep using 1,2,3 and task your husband with coming up with clever ways of making numbers fun, and you'll not have any trouble at all.
I really think kids learn quickly that numbers are rather neutral in the good/bad dichotomy. If this is a serious concern, the best way to neutralize the situation would be to make sure you use positive number examples as well. Such as, when you give him a treat, like M&M's or a snack like cheerios, ask him to count them to see how many he has. If he counts correctly perhaps even give him a few more.
First, I would reassure you, as did one of the other responses, that counting will not impact is perception like/dislike of math. In the mind of the child, one is about time and the other is altogether different.
Second, I would actually suggest reversing your counting. I know it seems like a simple difference and in the end - even to a child it isn't a big difference, but 3,2,1, does actually work better in my experience (preschool teacher and mother of my own).
Third, I would also suggest that perhaps it isn't a problem of your child not understanding that you "mean business" but perhaps he is hearing "no" too much.
Please don't get me wrong - kids need to be told no, AND yours needs to stay out of the toilet, but one of the problems parents run into is when we say no too much it loses its meaning. Think about it, when you hear a word too much, it stops meaning very much. What curse word do you hear most often? Does it sound as jarring to you as a curse word you rarely hear? I say "come on" to Alice all the time and it does absolutely nothing to speed her along, but if I say, "we've got to go quickly" she totally kicks it into gear (I need to be in less of a hurry with her is what it really comes down to for me). With things like playing in the toilet, your child might just be bored and need some redirection (offer up something more satisfying to you that will be fun to him to replace the toilet), whereas with running into the street you need an immediate response if you say "no" or "stop".
You might like my article, "the magic of toddler water play" if he likes splashing in the toilet, you might get a few "replacement" ideas with which to entice your little gentleman. pinchxeverything.blogspot.com