Having had poodles (who definitely DO need a trip a trip to the groomer unless you're very talented with shears), I don't really know what a groomer would do to a Labrador that would make it worthwhile. I do understand not wanting the mess of hair everywhere - for that using a self-serve dog wash station seems a good idea. I used to do that with my Rotties from time to time. A lot easier on the back, too.
Alternative idea: buying a little metal disk drain catch from a hardware store would help save your drains for do-it-at-home.
Considering that my Rotties got bathed at least a couple times a month, I thought the people here were nuts when I read about how they didn't bathe their dogs. Then I got Carbon and discovered they were right: he never needs a bath. He's had one since I've had him on vet's orders due to a medical issue. It didn't make him smell better since he already smells good. Just made him wet.
If Shamas is stinky, maybe have a look into his diet and/or a regular wipe down and brushing. Adding salmon oil to Carbon's diet made a difference, not in smell but in fur and skin health. Natural grooming sprays are another idea: I used to use them for in-betweens with my Rotties. I'd do a brushing, spritz on, rub down, and brush again. Also great for helping with shedding.