I would never use a 'glue', but I do use a 3M sealant that is supplied by my parts house and is intended for light industrial needs/appliances, etc.
This stuff is red. It fills gaps, peaks and valleys left in parts when new seals are applied to old parts. Wear and tear and rust residue, etc. can cause old tub parts not to seal as well to new neoprene seals, especially as well as they did when the tub was new. Adding this sealant fills the gaps and makes a much better seal. I like it because it sticks well, yet can be peeled off later. My mentor used this, and I never questioned his choice, nor have I ever used anything else. I've completely used up about 5 tubes of the stuff over the years on close to 70 machines. I suspect it is in stock at most or many parts places. I recommeded that RevvinKevin in Long Beach get some and he found it at his parts place too.
There was a 10-year hiatus in my repair work, until I found AW.org and got re-energized, and believe it or not, my 10 year old "tube of goo" was fine and I finished it off this past summer. Pretty good stuff....My dad has used the same to close cracks in a couple frozen bird baths after a surprise freeze and it's lasted for years. I also use it to cover up rust-spots in tubs and centerposts (vs. using Rust-Oleum).
As to the parts in the tub repair kit - there are only enough parts for one machine - four bolts, four washers and four rubber gaskets/seals. Some parts from Whirlpool come 'bulk-packed' and there are probably 25 kits in a box from the factory. The reason the kit has new bolts dawned on me today while reading this...the original bolts have a raised pattern underneath to "grab" onto the original rubber washer. When installed, the new bolts match up to the steel washer, so they need to be perfectly flat. The original bolts are wrench or socket driven, whereas the repair kit bolts are either flat-blade or phillips head, and take longer to install (this is why, L, that your service guy didn't want to use them).
G