Any of the Spa parts places on the web sell silicone donut gaskets that make resealing jets pretty straight forward. I definitely recommend using these instead of trying to reseal the jets with gobs of liquid silicone from a tube. Any bit of movement will break the seal on the goop, and you're back where you started.
The hardest part is figuring out which of the hundreds of jet parts/gaskets etc. that are listed on the site are actually the ones you need. I've got a box full of parts that looked correct in the picture, but were all wrong when they arrived. The other hard part is figuring out how to unscrew/remove the jet body from the tub without breaking it, since most of the jet tend to become brittle with age/chlorine exposure. I'd plan to buy a few replacements. Some of the smaller 1" jets have a cover that pops off, revealing a hex head socket in the jet well that you can use to unscrew and remove the threaded jet insert on the tub side from the jet body on the backside. Be careful not to bend the 'flexible' pvc tubing much or it can start to leak, especially where it enters the jet body.