[Raak]It is explained in OneLook (halituous=like breath; vaporous) and the line is supposed to mean that you end up as smoke instead of reaching nirvana if you are stupid enough to use that drug (please also note the attemt to get a double rhyme with line 1).
[Marc] I believe the usual retort to "age before beauty" is "pearls before swine". :) Continuing from what I take is UK's second line of a limerick beginning with your last line... I must first get my coat