I have tried the comb thing with the battery in that zaps them and it works well. I think it is called the robi comb or something like that. It has a setting for checking and one for zapping. I have used the conditioner technique too with the metal comb with extra long teeth. Derbac M which you leave on over night did work although I know some people do not like using lotions. We have been lucky not to have them too often but if I find one that is it! I can't think of anything else til they are gone!!
I did once have children for a sleepover who were both alive with them and I mean you could see them running about!!! It was the first time I had ever come across them so I was a bit freaked out. I told the mum next day who said "oh yes I know I thought they did"
Good luck Scarlett. I might do a bit of an inspection later.