I had to quit using my hands for jelqing because of joint pain. I have osteoarthritis in both thumbs partly because I have always used my hands as "tools" and have put way too much stress on the joints. The other reason for the osteoarthritis is hereditary (thanks, mom).
I have used the Jelq device for several years with great results, with no joint pain at all. Sure, it’s overpriced, and if you are so inclined you can probably make one from "canning tongs" or "jar lifters" (used to remove sterilized jars from a pressure cooker when doing home canning of fruits and vegetables).
In using the Jelq Device, I have never had a problem of using too much force. As with all devices, it can certainly cause problems if it is used incorrectly.
In my case, I could not jelq without it.
(The noise you hear from cracking your knuckles is a result of releasing small amounts of gas from the interior of your joints.)
Here’s what Wikipedia says:
Cracking joints - Wikipedia
-damfino