How long do you wait for a check to clear

Why did you not ask for a certified check from him?

as long as the check is in the buyers name and to give it 6to8days to clear. I would go directly down to the bank to talk to a rep and make sure the cash cleared and is in your account.

Check the buyer's feedback. That should give you some level of confidence. If there is no feedback, wait 21 days to play it safe. I once cashed a check at the bank and then deposited the cash. 14 days later, they took the money out of my account and said that the guy that wrote the check placed a stop payment on it. I asked how if I cashed it at the time could they possibly do that. They (Bank of America) said too bad. I was out $3300.

According to the manager of my local Wells Fargo bank, the recommendation is 10 business days for clearance for personal checks; bank money orders; and bank certified checks. All of the preceding can be rescinded during the passage through the money system. Only Postal Money Orders clear immediately.

If the check is from a buyer and bank is in the USA, the seller's address and bank is in the USA... 8 to 10 working days... it's what folks say. (when actually the check will be processed overnight the first evening! But the check might come back.. so you should wait a week.
BUT: it the buyer or seller is in another country!! "danger, Will Robinson, Danger".
A two country check could come back MONTHS later as no good, depending on the countries involved. So no way would i ever use a two country personal check.. Use a bank transfer. (and I ask why did you not do a bank transfer? it is super safe, and all they need is your bank routing number Once the money is transferred, it is yours. period.(check #s and possibly the international bank routing number, which you can ask anyone at your bank for.)
I would assume you felt the buyer was trustworthy enough to just get the check, and send the stuff. Otherwise why would you do it, silly?
I have accepted personal checks from a few folks. But only for small enough things I can live with a bad result.
And.. I would never do it if the buyer asked to do it. That adds a lot of possible fraud risk into the equation. I am the one who says: Hey, just send me a personal check and it is OK.