I've used Slime for over 20 years, Sliming my own tubes. When you use Slime, you gotta keep it rolling when there's a hole. Pump it up, keep it rolling.
Never ever touch the valve stem earlier than 8 or later than 4. 10 or 2 if possible!
If you roll it right and you have a good liner, Slime will seal up to a .125" hole, even a few of em.
Mess? You're doing it wrong, don't take it apart! But a garden hose fixes any Slime mess!
Growing up in the Cambrian area of San Jose in the late 80's there were goatheads
everywhere before the 85 freeway was built.
Things would travel from that empty strip of land North and South. I had tubes with a dozen or two punctures that Slime kept going for thousands of miles.
No more patching was the best part, because I was patching 1-5x every 100 miles before I used Slime.
If I ran out of Slime inside the tube I'd just re-Slime it 6-8oz. I rarely have had to remove my wheels and I really like that.
I pedaled over 50,000 miles in San Jose and Los Gatos. I found out bleeding Predator blood green means gotta go gotta go!
Slime doesn't really like cold, but I used it down to 20F in North Dakota for 5000 miles without a tube replacement. Keep it rolling lol
If your bike sits in the sun long, then it can cause the Slime to lose a seal or dozen. Gotta pump it up and start rolling.
Of course a nice rim strip, quality tube, and a tire liner can be very helpful on a rear tire.
Michelin has a new tube,
the Protek Max, that pinches holes shut and has it's own fluid inside.
I'll be switching to them myself next time I have to replace a tube, which I don't forsee as being soon!