I use a hand coffee bean grinder. The one I've got, you can adjust the grind from fine to rough depending on how you want to use the end product. It's a cheap option and I'm on my third season with it now. I use it on 4mm pellets usually but it handles 6mm ok too
It can attaches to any countertop in a snap with its "clamp-on-style" design. Large capacity grinder Hopper allows you to grind large batches quickly and easily. Also works great with nuts coffee, herbs, spices, seeds, etc.
Easy to adjust grind and takes about 5 mins a kg if you give it some welly. I chose to do it when the other half and next door neighbour are out as it is a bit noisy!
I got one of these of eBay for around fifty pounds. You can blast large amounts of pellets for ground bait and paste. Saving money in the long run. Coffee grinders are not powerful enough and will burn out. Plus you can only do small amounts.
I considered getting something like that which uses a lot of power, but why would I want to grind up a kg of pellets, rather than just buy a bag of already crushed ones? Would that not be a cheaper option?
I tend to rotate my pellets between method feeders and as an additive to a groundbait/feeder mix. Generally I only need to grind up small quantities so I use a hand grinder
Other than hookbait or method feeder fill, my pellets (either krill or vanilla) are ground and used as an additive to my feeder mix depending on what I am targetting (I also use 2mm pellets in a feeder mix too). I've tried using bulk buy standard pellets, but find find the smaller bags with particular flavouring more effective mixed (or not) with standard feeder/groundbait bag content. I'm finding Sonubaits bags particularly effective, but Ringers is ok too
You can take them down to dust or crumb to add to a groundbait mix, or grind down to small particle to use in a pva bag with a 10mm on a hair.
The small ones 1.5mm are great but more expensive, buying 20kg of 8 or 10 mm is way much cheaper, and all it take is a bit of effort(manual not electric)