This is a really good point about temperature. When I was younger, I decided to coat my own paper. I made a lovely Bromide emulsion, dissolved gelatin in hot water, added silver nitrate and potassium bromide. I cured it overnight it a convection oven, the chilled it. The result white Jello. All done in safelight illumination. I came to the wash step. I couldn't quite believe it would work, but it did. I minced up the cold white emulsion, then washed it in a contraption that used a large Paterson tank and cotton flannel, I washed that gelatin for an hour in cold tap water. It didn't dissolve one little bit.Surfactant + gelatin + room temperature rinse sometimes = small amounts of "gunk" in the nooks and crannies in and on a developing reel.
Doesn't damage the reel, but doesn't do the film or the loading process any good.
Moral of the story if you want to get the gunk out, use really hot water. All my reels, last step, go into a bucket of 45°C or hotter water.
Just give them a hot water rinse after each use before you put them out to dry.

