The first night, after we covered him with the oil... it suddenly dawned on me that he is allergic to nuts and that neem could be a problem. thankfully it wasn't. If you are worried, just try a small patch and see what happens.
i bought mine from a local herb store, they make it themselves I think... I looke at whole foods and wild oats, they didn't have it. I think i lucked into it at the herb store. i think you can find it on-line too. if you research neem, you see its very good for eczema, even if you are not concerned about parasites. it is very rich and thick oil.
re the carpet, not sure what to say... i tore all mine out when we figured out he had allergies. i hate carpet. the hardwood floors under the carpet were in ok shape, so i just left it.
a laundry ball... A forum member sent me one, you use it in place of detergent. something inside the ball works to break down dirt. we find it works on all but the toughest oily clothes (neem).