I love DE. I especially use it in the areas of the house where the animals sleep.
My nephew came to visit and had lice and the DE even helped to get rid of those where he slept... Of course I did all the other stuff of washing everything in hot water and treating his head but I sprinkled DE in his pillow and no one else got them and they didn't return....
I use Ivermec on my animals and I know there are those that disagree with me but I do like it better than Advantage, or Frontline... If you want to put something on your animal to get rid of fleas, worms, ticks, then Ivermec is great. The downside is it does have to be applied every two weeks... but it costs a lot less and you use very little.... I've not had one animal with an over dose and no issues with pests on my animals...
Small patches of hair loss on cats is not an uncommon side effect of topical flea preventatives. It's less common with advantage and frontline than with revolution but it happens. Usually just switching what you use gets rid of the side effect but i would never use revolution on an animal that had that side effect since it's much more likely.
Whether frontline or advantage works is dependent on your area. I've said it several times. With the popularity of flea preventatives these days it's caused some resistent pests the same as using chemical dewormers in livestock all the time. It's best to ask your vet what works in your area since that will change from year to year. Generally whatever the vets are selling is what currently works. Since revolution is not as popular it has proven to be effective when all the others fail but again the side effect risk is slightly higher and hairloss is a common one for cats. For some reason the most resistent strain of fleas I encountered was on hamsters and the only thing that saved ones life was revolution. The others died either from the attempts to treat them, any attempt to wash a hamster is about as dangerous as any attempt to measure and apply chemicals, or the loss of blood to the fleas since they were so small.
Not you again.
Didn't I already say cats are sensitive to ivermectin... Do not give or apply ivermectin to a cat without good medical knowledge or the advice of a vet. Also ivermectin wears off in 7days not 2 weeks so with your plan you've got a 1 week gap where your animals are picking stuff back up again.