You both are perfectly right about "awl". However, this nickname had double meaning. The second one was based on the homonym of the Russian word "shilo". Technically it means awl, but in some AF circles (but not in Navy aviation) it was a jargon word for the liquid (rich of alcohol) used in the anti-icing systems back in 60's and 70's. Tu-22 contained a huge amount of it (some 400+litres), more than a double of the Mig-25 capacity which was called "flying bar" for that. Therefore at a certain point of time all those liquids were replaced by "non-potable" ones. Game over, bars closed :-)
KenV, your considerations about old Soviet system make sense, but all this has nothing to do with nicknaming of planes. Similarly, Russian pilots do not have nicknames (call signes) either.