Reddit reviews SILICONE CAULK RMVR 3OZ by MCKANICA MfrPartNo 0354

A couple ways to approach it. The "proper" way would be to remove the jet and remove the silicon from it and the tub (http://www.amazon.com/Mckanica-Caulk-3-Oz-Silicone/dp/B000PVT1P4/) and then re-silicone it. Depending on the jet, it might be extremely difficult to get removed - and might require buying a tool.

The hack'ish way to fix it would be to simply add silicone around the interface where it is leaking (after draining the water below that level, obviously). The challenge is that since water flows so well, you can't be sure exactly where it is leaking, so that pretty much means putting extra silicone around the whole jet. Main downside to this is that there is no guarantee it'll fix it, mainly because silicone doesn't bond well to dried silicone. So if there is any meaningful amount of existing silicone, you'd want to cut it down as much as possible, and then to maximize your chances, you'd want to put a fair amount on to maximize adhesion to the tub and jet.

Here's the silicone you use:
http://www.spadepot.com/shop/Clear-Silicone-Spa-Pool-Adhesive-Sealant-10-oz-P9282C149.aspx

First off, i seriously doubt it is caulk (in the traditional sense). I t is most likely a contruction adheasive. From the looks of it, probably Power-Grab. This is a polyurethane adheasive that is pretty much permeneat. You could try a caulk remover, but it may not do much. The one I linked is water based so it's probably a bit milder than some of the other (more effective) removers like McKanica. Realistically, those adhesive can be dissolved though. The manufacturers basically recommend using a thin wire to 'cut' the adhesive free. I would try the plastic razor and heat. You MIGHT be able to soften it some with mineral oil which will also give the benefit of lubricating your razor. Good luck!!!