I really hate when people do that, this is considered a hazmat scenario and there are proper chemicals that are used for a reason with these types of situations.

The pilot holes for the lag bolts are typically 1/16-1/8 of an inch smaller than the diameter of the lag bolt making the mechanical base act as a sub flashing, and then there is also a chemical sealant (caulking, geo-cell, Henry's... depending on the installer) sandwiched between the roof decking/paper and the mechanical base.

I have a job in chemical industry (manager) and a good salary (90k a year).I started with buy & hold real estate in 2016.

At times, the odor was so strong you can smell it walking in the main entrance into the lobby.There's been some discussions here on remediating it with chemicals.

You can use any toxic combination of cleaning chemicals and it won’t damage the floor.

Replace all TCs, drain water, add chemicals in all toilets to kill roots in the system.

Heat and chemical.

The pest company should take on treatment for termites, framing work, and anything that requires chemical treatment. 

Please make sure you or workers wear cartridge style air respirator when removing that carpet and spraying with any of these strong chemicals also probably should wear a white tyvek style suit etc. 

Septic companies around here dont clean drainfield lines , they just replace ( around $ 20K with the new systems ) So I am figuring on about 200 bucks in stone and 80 dollars in fittings and 100 in chemicals .