If I drop the glass toy, can I use it again?

Youshouldlookforanyfracturesorchipsbeforeusingitagain. Will the glass toy break if. 

I heat it or cool it?

Theborosilicateglassendureshighandcoldtemperatures.Youcanplaceitinthefreezerorwarm water without worrying about cracking or chipping. You should test the temperature before putting it directly in your genitals.

How should I clean the glass toy?

Water and soap will do fine. Glass is a non-porous material, meaning that it does not absorb any bacteria, making it body-safe, hygienic and easy to clean.