you are right about flea colors they do not work at all.. they only work around the neck area, not the whole body. the best way to get rid of them is to spray or bomb your place, but make sure your chinchillas are in a safe place.. they also have sprays that work.. i have had to use the sprays myself.. and my chins have their own bedroom which no carpeting so what i did was close the door and put towels near the bottom of the door [the inch gap] and sprayed.. i actually sprayed the rooms at different times so it didn't get over bearing with smell.. you can get something with residual effects so spraying that way will work.. i also sprayed again in about 4 or 6 weeks [whatever the bottle said] for when the eggs hatched.. also vacumn alot and then empty it out outside. also do your furniture.
as for if chins can get fleas, i have actually saw a few times that they can around their face area because the fur in thin, but what i read could be wrong... if you want to make sure, you may want to check with your vet.
a great way to find out how bad the infestion with the fleas are is to do this:
if you have a lamp or some type of light that can actually be right over a dish, fill the dish with water and some detergent, at night when you go to bed, have all the lights off and just put that one lamp on.. what happens is that the fleas jump for the light and end up in the dish with the soap and die.. so when you get up the next day, if you have alot of fleas you have a big infestion, if you have just a few its not that bad, if you have none, i would repeat it again in another room..
i hope that made sense.
best of luck to you.