no, powerwash the furs clean ( this is much easier than fleshing by hand), the mix half borax and half alum powder together and add a few ounces of water. you want a thickness similar to mashed potatoes. I've copied the alumni use below
https://www.amazon.com/dp/B07M8DLW9T?ref=ppx_pop_mob_ap_share
Depends on whether you are hard or soft tanning. Hard tan is easier and only requires borax and alum paste. Soft tan uses any variety of chemicals to put "clean" oil back into the hide so it can be made into garments etc.
garage sales are not taxable events unless they produce a gain from sale. this would only be the case if the item had 0 value and you received anything above that. Unless you are in the "trade" of 2nd hand sales, losses from a garage sale or any others would be personal losses that would not be...
You cannot deduct losses on items used for your personal life. The only tax consequence where you would need proof would be a gain from sale which is highly unlikely. Everyone is getting worked up about the 600$ thing, but it is really not that important. It was created and passed to crack down...
This is a good video for those looking to begin tanning at home. You will have to modify it some to fir your needs and climate but the general concept is correct.