Haunted is incorrigible! :rofl:
I think the word "sweetening", as used in pipe lingo, doesn't literally mean that the pipe will taste sweeter.
That should be achieved by one's choice in tobacco blends.
Rather, cleaning with Everclear, for example, sweetens the pipe solely by removing bitter and otherwise unpleasant
tastes from a dirty pipe. That we use other liquors with a sweet residual taste shouldn't cloud the issue.
I think it is a good practice to avoid cleaners with a high water content as moisture is not friendly to wood. To that end, alcohols, which are effective solvents for tars, oils and grime, are also hygroscopic (absorb moisture), and make ideal cleaners.