A neat use of a good theme. The final touch should satisfy all tastes.
As a scientist, I consider that any method available is acceptable for solving problems. Indeed, there are some scientific problems that can only be solved by recourse to electronic databases and search engines. Anyone who didn't use such aids would be considered very peculiar. I therefore do not consider the use of engines such as Quinapalus to be cheating. The prime purpose of a puzzle is to give entertainment, and anything that enables that should be acceptable. Having said that, I would encourage others to give the cold solving a try before going to the engine. In this case the Playfair yielded up quite quickly, because two of the encoded pairs were in the same column, which is rather unusual for such problems; when I saw that, it fell out quite easily and gave me more pleasure than I think I would have had from using the engine.
For those who have not come across the theme word before, there are actually five words (perhaps six) for different forms of this type of construction, which compounds the problem of solving. Chambers includes three of them (perhaps because the others do not have English equivalents).
Incidentally, is this the first time that a Listener puzzle has dealt with copulation? :>)