When you are learning how to use a carto tank, I think it's just a given that you will go through cartos at an alarming rate. I know that I almost gave up, thinking it was just a stupid delivery system and would never work and people were just ....ing with me when they said it was awesome. Now, aside from a very occasional carto that just won't wick (maybe filler is too compacted?) they work great for me.
I use boge cartos with one hole punched with a saddle valve. My juice is 50/50 pg/VG and I add 5ml vodka per 100ml juice (DIY) to thin it down a little. I used to do slots with a dremel, but since I do hot swaps (swapping new cartos in without emptying the tank) I didn't like how the rough edges of the slots would tear up the gaskets of my tanks. But you can see from this thread that there are many different ways to get a carto tank to work. You just have to figure out what works for you. It is definitely fiddly at first, but once you figure it out it can be fantastic and fiddle free.
I use boge cartos with one hole punched with a saddle valve. My juice is 50/50 pg/VG and I add 5ml vodka per 100ml juice (DIY) to thin it down a little. I used to do slots with a dremel, but since I do hot swaps (swapping new cartos in without emptying the tank) I didn't like how the rough edges of the slots would tear up the gaskets of my tanks. But you can see from this thread that there are many different ways to get a carto tank to work. You just have to figure out what works for you. It is definitely fiddly at first, but once you figure it out it can be fantastic and fiddle free.