I am sick of buying $2 response pads. I heard that you could
Use 19mm o rings. Can anyone verify this and tell me where I could get them and if all 19mm brands work??
Just head down to the hardware store and try them in the oring groove. You may find you want a thicker or thinner one.
It really depends on the yoyo. As Schnayke sez, take it with you and see if you can find one that fits.
How often do I need to change them??
O-rings will outlast most any other component of the yoyo. I have 10 year old (or more) YYJ yoyos with o-rings that are fine.
You could just use flowable silicone on your yoyos. I found mine on a sale rack for $2 for a big tube of it.
Would you recommend a specific brand?? I have a horizon and a skyva that I want to put them on
I believe you can find some useful info on using flowable silicone, including brands, here: Useful modification & maintenance guides - Axles,Clean, repair, tune, fix yoyos
Pretty much everyone that doesn’t use replacement pads use some form of silicone. Nobody really uses o rings anymore.
Not entirely true…
A lot of true yoyojam enthusiasts do use o-rings 
So silicone?? Or would o rings do the trick.
I would personally silicone then you can use it on any yoyo without having to worry about what size.
Silicone will work, however if you don’t store it right it will just end up costing as much or more. Make sure you store it well. Since cost was your issue I thought I would throw that in there.
It’s not really that hard. As long as you put the cap back on after use and it’s not in really hot or cold temperatures, it’ll be fine.
Didn’t say it was hard, just pointing out if money is the issue he needs to do that part right.
So how should I store it???
Andy really said everything you need to know.
^^^
Sometimes when I do that, I have to pick just a bit of dry silicone off of the top, but then it’s good to go after that
Thanks for all the help. !! I’m going to try out monkey snot