Explaining why you didn't want him/her to stick the shop-vac hose in their mouth didn't work. The reason it didn't work could be because you yourself are not convinced that it's dangerous.
We talked about how dangerous it could be, but it was one of those times when my child pretends not to hear ...
I am actually not sure how dangerous this is.
If your child had been putting a sharp knife or a blowtorch or something obviously dangerous in their mouth, I'm sure your discussion with him/her would have been more emphatic and clear...and the kid would have stopped.
In this case, however, you probably shouldn't react the same way as if it were a knife or blowtorch... it's not about preventing him/her from doing it because it's extremely dangerous, but more ambiguously because it might be dangerous and you just don't think it's a good idea. That's harder for kids to understand and take seriously
Approach it like any other rule you set down for your family.
Kids at this age can't be expected to understand or agree with all the reasons for the rules you have. To help ensure they comply with the rules nonetheless:
- Make your expectations clear. e.g. We don't put shopvac hoses in our mouths.
- Make the consequences clear. e.g. If you put the shopvac hose in your mouth, you will have a time out for 5 minutes.
- Be consistent and follow through
- Keep the rules simple and minimal. e.g. if you have a rule for every small little thing, it's hard to remember them all.
Consistent reactions and consequences help ensure kids know what is expected of them. Too many little rules that are sometimes followed, sometimes not, make it confusing and difficult for kids to do what is expected of them.