And just a couple of notes from my experience.
I worked in a shop after the military. When a car came in with a tire that needed to be replaced that had Fix-a-Flat in it, we charged more, because it was so nasty to deal with. It smelled like rotten fish, blueberries, and an old, used condom. Seriously. It is the weirdest thing I’ve ever smelled. And we were told to avoid touching it, and to wash immediately if we did. I wouldn’t think it had anything corrosive in it, so I don’t know why they said that-- maybe it had a toxin that could be absorbed through the skin.
Second is, I used to bike everywhere. I would go to state parks, camp overnight, and bike back. A four hour ride was a nice afternoon.
There are tubes, and there are tubes. Pay for the expensive ones that claim to be puncture resistant. This was when I was in my 20s, and watching every dollar. I biked a minimum of 100 miles a week, seriously. I had rain gear, I had snow gear, I could carry a lot of Gatorade when it was 95°F. Unless I had to haul something that you couldn’t strap to a bike or carry in a backpack, or had to be somewhere that was just impossibly far away, like Terre Haute by 8am, I biked.
In about 10 years of being such a serious biker, I think I had one puncture. I changed the tube myself, pumped it up with the hand pump I carried, and it took about 20 minutes, because I knew how to do it-- I had practiced.
I did carry a cheap tube as my back-up, because I carried a couple, in case I pinched one. I also carried a patch kit, because it patching was possible, it was preferable.
After I did the emergency tube change on the road, I went to a shop ASAP, had a good tube installed, and the wheel trued, also, the tire checked to make sure the puncture in the tire wouldn’t damage the new tube. Sometimes the word back was that the tire was worn enough that since they were taking it off anyway, I might as well replace it. But I trusted the bike shop. The manager was the younger brother of a good friend of mine from high school, and I was a very loyal customer-- not someone they wanted to try to soak once and never see again.
So, basically, I say “No,” don’t “pre-slime.” Carry a patch kit, a new tube, a tire tool, and a hand pump. Also, a cell phone, something that didn’t exist when I biked. And practice changing a tube before you need to do it in an emergency.
Also, pay for the good tubes that are puncture-resistant.