It seems our 6 month baby wants to take everything in her mouth, it would be nice if we were able to give her some natural food-based teethers, but which edible substances can be used as teethers? Do they require any processing and what kind?
A lot of people recommend cold carrots, but the problem with carrots is that the baby can break a piece off that is just the right size to choke him. If you try carrots, you should watch carefully, and preferably only allow him to gnaw on the fat end where he is only likely to get scrapings rather than chunks.
It is difficult to come up with a "natural" possibility, but what you are ideally looking for is something that dissolves and is unlikely to cause a choking hazard which can be frozen to be hard and cold for relief. You might try frozen waffles (make your own and freeze if you are concerned about the ingredients). Cut them into strips so that as one thaws and gets mushy, it can be replaced with a fresh one. Pancakes or biscuits might also be possibilities.
You could blend a fruit puree into an ice cube tray, freeze them, then put them in the fruit mesh bags like these.
You would have control over the recipe and the mesh bag would prevent the baby from getting more than they can handle. This would be messier especially now that it's not a whole fruit and actually a dripping ice cube. Strawberries/cherries/blueberries stain clothes very easily. So maybe stick with apples/pears. You could swap out the ice cube for a fresh one when it got too liquefied.
I did cold carrots for my daughter like Mary Jo said, giving her the fat end. She never chewed too much of it but of course she was monitored when she had the carrot. We also used the plastic teethers that you put in the fridge.
I know you said you wanted something edible but how about a frozen, clean washcloth? My kids LOVED this. I'd wet it, tie it in a knot, and freeze it. Not totally, just until it was stiff. They'd gnaw on it for hours. The thought of fabric in my mouth gives me the willies, truthfully, but as long as they r happy (and safe) I'm happy. I also used to give them whole, peeled apples. Since it's so big it's tough for them to get it into their mouth, thereby reducing the likelihood that they'll bite a piece off. Good luck!
As per the recommendation of the other answer by Mary , we tried crackers(biscuit) as teethers and it worked quite well since if some piece broke while gnawing then it instantly disintegrated with the infant saliva. Also carrots worked well but we had to monitor it.
Also our baby loves to gnaw a ripe jackfruit bulb. It seems to be the closest teether alternative which feels like the artificial ones, ofcourse you need to deseed it before giving the infant a large bulb.
As a parent, it is hard to watch your little one go through this painful process, which is why it is important to know all about teething so that you can offer your child every comfort while he/she is teething, and what remedies/toys are safe for them. If i can just add, by reading through a couple mom blogs, what i noticed a lot is new moms always wondering which is the “best” toy to buy the baby while teething. This is a difficult task because ultimately, it is whichever toy the baby chooses, which is why i strongly agree with buying a variety of toys and have the baby pick their favorite. Like in my experience, after going through multiple toys, my daughter finally fell in love with the Silicone Teething Mitten Baby Glove, which in my opinion, actually topped other teething toys. Teething Mitten glove, Protects baby`s hands from becoming chapped from excess chewing and saliva and also it stays on the baby’s hand comfortably with a secure velcro strap which makes it easy to carry around. Also the teething mitten glove will keep your baby entertained with its crinkle noise, attracting baby’s attention, and distracting the baby from the pain. I would definitely recommend the teething mitten glove to any parent new or not.