Hmmm. If you were to say "I did sample cannabis when I was at university but found that I did not like it....", it would merely imply that you might have continued to abuse it if you had "liked it".
I say again, there are plenty of non-drug abusers to choose from, particularly now that recruiters can afford to be very selective. And, out of interest, you might like to know that I never heard of anyone who admitted to a previous instance of drug-abuse ever getting beyond the initial UAS interview.