in some accents they rhyme because of the cot-caught merger.

https://en.wikipedia.org/wiki/Cot%E2%80%93caught_merger

I'm curious how you pronounce locks and if you don't mind where you are from.

Walk: https://www.youtube.com/watch?v=gfkgn99Svfk

Talk: https://www.youtube.com/watch?v=BG9GBNr7kFk

Sock: https://www.youtube.com/watch?v=6cpffNd2GaA

Lock: https://www.youtube.com/watch?v=YPN_94VMk8Q

Sock and lock sound similar to me, and so do walk and talk. But walk/talk and sock/lock sound quite dissimilar.

Here in Canada all four rhyme, and are more similar to your sock/lock than your walk/talk.

In my accent, walk/talk/sock/lock all sound similar.

They rhyme in most American English dialects.

Can you post a video of someone pronouncing that? I have a hard time imaging how sock and talk can rhyme.

Sock: https://www.youtube.com/watch?v=eAslCof0N6Q

Talk: https://www.youtube.com/watch?v=gKoe_hDLTv4

Hence the joke book I heard of as a kid: "101 ways to wok your dog". Tock and talk are pronounced the same, as is wok (the cooking instrument) and walk.

Is this really true in most American accents? In my midwestern accent “tock” and “talk” absolutely don’t rhyme, but maybe I’m the outlier here.

in the northwest (Vancouver, BC area) tock and talk rhyme (they are pretty much homonyms).

Socks imply shoes. And shoes imply walkies.

Yep, my dogs are tuned into sock acquisition as a precursor to outside. Which says a lot about how COVID WFH has trended towards the sockless.