I get my plants from HD and Lowes too. I clean/wash them all with Dawn Dishwashing Liquid... If you can do it outside it's much less messy!!! After doing a fair amount of soaping up each leaf the best that I can, I rinse the entire plant until I feel like the soap is gone... Sometimes I then will leave the ant outside exposed to the elements,,, weather permitting!
I figure if it's safe enough to us on the "oil spill animals" it's safe enough for my guys!!! I've never had any issues with it!!!