I used frozen fruit when Sol was teething. You should be able to find a mesh pacifier looking thing at most baby supply stores. These little things are perfect for putting fruit and ice cubes into. Sol used to suck that fruit until it was nothing more than a pulpy mess lol. I believe there are pics of his first raspberry experience somewhere on here. I think it was during his first teething session – 4th month.
I had also heard that frozen bagels were a good teething tool, but Sol never really took to that one. I tried it when he was about 6 or 8 months. The bread of the bagels will pretty much melt as baby chews and sucks on it, so there is little risk of a choking hazard.
Pretty much for teething – I used frozen fruit, ice cubes, and orajel.