If you have no decor or plants then it would be safe to go with the chemical cure , if planted avoid it, when all the snails die you have to remove them fairly quickly as they can soon pollute your water,if it is planted you will never get them all.
Find a small bottle, place a catfish pellet in it and then sink to bottom of tank at lights out, after one hour remove and dispose of contents, repeat until clear of snails. 8)