We have a jetted tub that is 15yrs old & the plumbing is leaking off one of the 90's. The fittings are all stacked together off the actual jets so it's not just a simple cut out & replace. The section that is leaking off the 90 is a type of flex pipe that is in a bind so a split sleeve won't lay flat. I've had to cut out a section of tile & drywall just to get to the leak. Was hoping to do the repair myself but I'm starting to question it. Anyone had any luck with repairs to these ?

Check out "hysol" epoxy. Made by LOCTITE. This is what serious offshore fishermen use to patch holes in their boats below the water line if they have a leak. I manufactured jetted tubs for thirty years. We NEVER put "flex hose" in any kind of a "bind" for the very reason you mentioned.  If it is possible you can cut the flex hose and put a new 3/4" or 1" coupling on it and using flex hose or a multitude of fittings to tie it all back together. Even if the "patch" looks like a drunk snake it will not affect the workings of the system. I really need a pic to help.