Honey I am so sorry that your family has this problem. My sisters kids brought it home from school years ago and it took me all week to really get them gone. First the boys were ok about a crew cut, her husbands hair was thining so not a problem. The two girls and she had long hair and think. I used the rid product.....and the thin metal comb. I worked section by section just combing. In the mean time, sister took all sheets, bedding, pillow cases, couch blankets and pillows and swept, beat, washed and sprayed.
Reinvestation is a big problem and remooving the little nit on the shaft. If your husband will comb and comb a section this will help so much. Use a spot lamp, like if he has a workshop clip on one, they are at lowes adn
Walmart inexpensive. the more light the easier to spot.
Check your coats, any laundry that could have been touched. I am not sure I think with sis we put coats outside in the sun then dryer.
Hats, hotwater and before clothes went in, add bleach.
I just got over a second round of fleas for five cats and that was no fun either.
If I were close enough I would come right over and help. I know from years of hairdressing career, how stressful it is.
As far as olive oil, that is new on me, we always used the one with a med in it,
How did oil come out of your hair?
hugs
dianne