Questions About Fip

I have read a lot about FIP (wet and dry). But I get confused as to when a new cat can be brought into a home after a cat has died from FIP. Also, what protocol to follow afterwards. I've seen that you should wait two weeks all the way up to six months to bring a new cat into the home. I've read all you need to do is clean up litterboxes, dishes, etc. all the way up to needing to throw EVERYTHING out - including cat trees, toys, etc.
There's just so much conflicting information and I wonder if anyone truly knows. It seems as if the coronavirus can't survive outside the body for terribly long so my actual question is this... If a person were to just wait a few months, do regular cleaning, would the virus just die off of carpet, toys, cat trees, etc and you wouldn't need to throw anything out? Just seems strange to me that if it eventually dies by being exposed to the environment anyway, why would anyone ever need to throw out a cat tree or something like that???
Thank you!

Although it's been awhile I can tell you what my personal experience was when we had an adult cat and later brought in a kitten who was just shy of 1 year old. Unfortunately the older resident cat never accepted the kitten who lived with us for 2 years before being diagnosed with FIP at age 3. The kitten spent a lot of time in our bedroom, his choice, so when he passed away I completely closed off that room to our adult cat. I thoroughly cleaned, vacuumed and disposed of anything the kitten came in contact with, e.g. bowls, toys, kitty blanket, etc. Since I am an extremely cautious person I kept the bedroom door closed for a year. I know that may have been overdoing it but I didn't want to take any chances or feel guilty if our older cat showed signs of illness which she never did.

Here is a TCS thread that discusses this subject:
Future cats after FIP death?

And another article that goes into more detail:
Getting Another Cat After a Diagnosis of FIP - Animal Medical Center - New York City

This is a great question, so little is understood about FIP that I think there are divided answers. I think vets are conservative and suggest waiting periods of various lengths. FIP appears to be generally contagious cat to cat, not environment to cat, however coronavirus (cold viruses) do live outside the body for a period of time. So if it were me, i would clean the home well, probably toss out things that the cat had a lot of contact with, litter boxes, scratching posts, and wait at least a few weeks. Did you have a cat die of FIP recently and are you looking to get another cat soon?