I want to ride with as much less things as possible. I don't mind the weight, but just the bulky-ness. So what do you guys think of this slime tire sealant thing? Are any of you here using it at the moment? Does it work well? I want to put this in the tires and carry a co2 pump and maybe a spare tube.

https://www.slime.com/category_3_Tire-Sealant.html

For mtb wider tires like 1.75" and up width it works well. For hi press narrower hybrid or road tires, not so much. I ride slime in my mtb, and it had patched a few holes, but still, I wouldn't go anywhere further away without at least one spare tube and a patch kit. It simply makes it possible that you will go longer between tube replacements, not completely eliminate them.
Also, weight of the slime makes it noticeably harder to accelerate, as it sloshes around the tubes. Not that much, but definitively noticeable. And sometimes it is known to plug the things its not supposed to, like valve cores, so sometimes a valve core tool and a few replacement valve cores can come in handy if you do not wish to have to throw away an otherwise perfectly good tube. So it has it pros and cons, its up to you to decide.

For the reasons whitecat posted, I found it to be more trouble than it's worth.

I agree with what others have said, I use slime on my mtn bike (commute bike).
I also ride in the south bay, and this time of year there are goat head thorns on the road or path. Along my commute, there are stretches where I do not want to stop to fix a flat (not so safe). Using slime for the last 10 years, I've found that the goat head holes are patched by slime, and bigger holes are at least made to leak slower. So, at least I have been able to make it to either work or home to fix a flat after pumping the tire up and spinning the wheel while still on the road.
Now that I use slime and armadillo tires, no flats in the last year of commuting (about 7000 miles). Yes, slime makes it heavier and slower, but I'm already on a 55 lb mtn bike, so I'm used to slow. On a road bike, just get good tires and carry a patch kit and pump/inflator.

Spend some time polishing spokes and Rims after a major blowout and decide if there are other options that might work better for you.

I heard of someone having a hard time cleaning their Cat, after a tire blowout got the neon green stuff all over the Cat
when the tire blew out , pumping it up.

I've tried it in a couple of tubes, but for reasons mentioned above I've decided it's not worth the trouble and am weaning myself off of slime. In one case, slime converted a near "blowout" to a fast leak; that could be a safety feature if you're travelling really fast (I was just accelerating at the time).

I found Slime tubes to make the bike feel too darned sluggish. The difference was very noticeable. I moved to Slime tire liners and never looked back. The liners are almost completely invisible to me, and have protected very well. Just make sure to sand down the ends and corners of the Slime liners with wet/dry paper before installing.

The Cat must've been a riot to see under black light.

Thanks for your opinions guys. I find them very helpful from personnel usages. I don't think I would mind the cons if it helps me fix a puncture right away. It's going to be on my beach cruiser and commuting to work will be just around 5 miles top one way, maybe.