I read a bit more into Nashtide's method with vodka and will go with that to begin.
If I get to 5mg ED (probable) I will split the 20s into 4 like you suggest. I was interested in whether there's any reason not to split (most places outside this forum seem to say you shouldn't) but I'm sure there's no problem with it from people's experience here.
With current UK prices, it's less than $1/£1 per day for sure for daily use - awesome.