(snip) Wouldn't Ozite be just as likely to get dirty as carpet? (snip)
If you know anyone who installs medical imaging equipment they sometimes can get scrap lead sheet from demolition of old imaging rooms, or scrap from new installs. The guy I know in that business lives 500 miles away so it really doesn't help me.When installing lead sheet should you put screws or fasteners through it? I always thought fasteners transmit sounds, but I don't know how else you secure whatever covers the lead.
Glue: http://www.quietrock.com/soundproof-products/damping-glue.html
Cheapest most efficient under the floor is mass loaded vinyl I think. I buy it in 48-96 wide roll. 1/8" thick. Roll out between floors. On the walls upholstrey foam with cloth, or vinyl works great. Just my 2 cents!!