isn't Milton just dilute bleach ? I use Tesco dilute bleach - dirt cheap..........
I am lazy so like the ease of throwing a couple in a washing up bowl full of water knowing they will do the job, they work out just over 5 pence each so price isn't an issue.
Milton tablets contains 1% sodium hypochlorite (NaClO) and 16.5% sodium chloride (NaCl; common salt). 1:80 dilution is used to sterilise babies' feeding utensils, including baby bottles. It is sold in dissolvable tablets which are then mixed with cold water and placed in a lidded bucket.