It does need cross pollination. Not sure if a clone will work but an unrelated caerulea or some of the other varieties will work. Caerulea sets fruit easily but in all the years I've grown it I always get empty fruit. This year I've hand pollinated with selected varieties and am just waiting to see if I get seeds or more little balloons. I think I'm one of the few that gets seedless fruit from caerulea. I've never heard of a palatable caerulea.

I have heard of some people eating P. caerulea fruit with sugar, but I just don't think any amount of sugar could make them taste good. For a tasty hardy Passiflora, P. incarnata is a much better choice.

I Have, There was a one in Selsey Bill that Have VERY tasty Fruit, Granny thought it might be because it was on the coast but in a Very sheltered place with Lots of Sun...