Ventilate and get a good chem respirator rated for Acetone.

I pull the carpet/pad and tack strip, use a  bleach water solution to mop subfloor  (with respirator) rinse,  then after dry, I also use the oil based kilz on subfloor (pretty thick, respirator a must); then, and I am rooting for you Jeff, and hoping you do not need the next step..... but if you still smell it.....

it is worth a try to tsp, rinse, then kilz (I would use old school oil based with respirator) or shellac seal the walls..

See if he will do it if you spring for a respirator and tyvek suit (should run you about $50-$60) or see if you can find another appraisor

You also have to pay fairly well to keep competent employees that are willing to work on a hot roof all summer in 100 degree Central Valley heat spraying foam in tyvek suits and respirators.

And rabbit pee is meant to be the worse - and it damages hardwood floors quite badly - it literally strips the coating off the floor.But removing carpet is easy, buy a mask, and get on your hands and knees with a knife, pry bar, whatever.Really recommend these:http://t.homedepot.com/p/3M-Professional-Multi-Purpose-Respirator-62023HA1-A/202080144/ And then burn your clothes afterwards.

A few key points. 1) this stuff is toxic and can hurt you or worse (be 100% sure you buy respirator and have fresh air blown in) and only do it in unoccupied unit. maybe worst (toxic) stuff I have worked with residentially... bugs were dropping dead by the window...2) no it is not forever permanent--but what it is. 3) prep, prep, and more prep. 4) I would use it on a surround that gets some water splash--not where it gets constant water or submersed (like actual tub, need heavy duty stuff there). 5) follow all instructions and research well....cheap (25-30 bucks + roller)--but a lot of prep labor. it would make the surround look nice enough for the sale and/or get you through a few tenancies on a shoestring until you or someone replaces it.

The main thing you need to work safely with the interior variety is to set up box fans (I use two of the popular Lasko Wind Machines) for forced ventilation, but you should also wear a reusable respirator with VOC cartridges.

Make sure you have a proper respirator that can filter the particulates for your sprayer.I have a Graco model and I use it for exterior painting, interior trim, and for priming the walls. 

Guys with space suits and respirators are expensive--if you are determined to remove any and all lead or asbestos, figure that expense into your pro forma.Disclosure:  I am not a certified lead paint remediator, nor an asbestos abator.