[capt_noonie]

I wouldn't trust the Walmart flea stuff. Since it's your sister, why don't you ask her if she wants to go halfs with you on the good flea stuff? Just tell her her dogs has fleas and they stuff she's using isn't working, and that your dogs gets flea allergy. (My Uni gets BAD flea allergy, so if this were me, I'd say no more visiting unless she gets better flea stuff, not worth it to put mine through something like that.)