Beski - these tubs can get quite nasty. The back sides of the jets will be fully sealed and quite hard to access without removing the tub completely.
You might be able to seal the jets with something like SikaFlex. Perhaps you could find a nice solid white cover and affect this on over top of the jet locations.
Could you upload a picture of what the jets look like? I would not want to try removing any attachments and would think you first should clean the lines, then drain the lines, then give it some time to dry (maybe a fan inside the tub for a couple days) then pack the hose lines and something like a sika flex.
When they build custom hot tubs often these jets are are just sealed in position with a waterproof sealant.
Have you tried calling the maker of the tub? Maybe they have a better solution???