I recommend you give the vaseline/cotton another try. It works very well for me....always. Make sure you have used
real cotton not some poly substitute. Mine is coated with vaseline not dripping, but coated. I place a tuft that I have pulled apart some on a curl of wood....
Then holding the firesteel right on the cotton, I hold the knife spine steady
and pull the firesteel.
Transfer the chip to your prepared fire and away it goes
I stuff my cotton into a small candy tin. I usually take a couple of cotton balls and lay on some vaseline, put these in the tin, cover with a pulled out cotton ball, squash with my thumb, lay on some vaseline, another pulled out cotton ball, squash.....ad nasuem until the tin is stuffed full. This forces the vaseline through the cotton and any excess is squeezed out. I pull out one or half of one cotton ball for a typical spark strike. This little flat Clik-Clak tin holds plenty of pieces.
For my kits I have made Tinder Straws...a plastic drinking straw stuffed with vaseline/cotton with the ends folded over and secured with another piece of plastic straw. These work great to keep the PSK from being coated with vaseline.
There are probably one or more threads here about tinder straws.