I just learned about using DE for fleas today and am very interested since my cat is allergic to flea bites and who wants those little critters in the house anyway right? My main concern is my grandson.. I read that you can sprinkle the DE on carpet and vacumn.. how long do you leave it on before vacumning and is there any risk to my grandson if he is playing on the floor ... and can you sprinkle on furniture also and then vacumn it? Very urgent response please .. I'm taking my cat to Vet today and want to get on with cleaning up any fleas that must be here ... my pets are totally inside pets but she got bit somehow.. must have been a hitch hiking flea on one of us coming in...