We've been doing this for years. I bring back lots of amenity kits and have given them to my daughter, who picks out the luxury facial moisturizer of some such but sorts the stuff that would be useful to homeless shelters and brings the stash over. Portable toothbrushes, toothpaste, soap, shampoos from hotels, etc. is well received. With the TSA (Security Theater) rules banning more than one baggy worth of bottles, I'm probably am bringing back a fair bit less now than prior to the rules but what we bring is still valued.