Ok,, just purchased a test kit for my safety and this may sound like a dumb question, but when you use the kit (classic) for example will it ruin your pill if you use to much?
Not at all - the scraping you take really is fraction of the overall amount. I find a couple of scrokes lightly across the side of a pill with a key is all you need.
candla, from your post it sounds like maybe you are thinking of putting the liquid on the whole pill! This isn't how you do it! Like soma said, you scrape of a tiny bit of the powder and test that. The test kit is corrosive and will eat into clothing and skin so don't swallow any!!!!
My apologies if you were testing it the correct way, just don't want you to do anything silly