Sorry to hear you got bugs. It is possible they're harmless. There are many tiny bugs that feed on dead and decaying matter in soil. There is a very common sub millimeter bug in my garden soil and grass in the summer and fall. This bug came to mind when I read your post, but searching the net didn't yield a picture or name of the bug I was trying to find. They remind me of a cross between a termite and a wood louse(aka roly poly or pill bug) except waaay smaller.
Anyways, hydrogen peroxide would get my first vote, then bleach, maybe neem oil if you had it.