I mean this really seriously - I want to "prove", that it can have an effect on performance - for that I needed quite some rise in mean 3-dart average - good question, what would be credible as anecdotal evidence?
You mean conducting an experiment that may show that ld practice improves real practice? I have read in an article somewhere that musicians and athletes often visualize performing before important events, and possibly those who can ld may do this in dreams too. I know from practice that solving exercises in a dream (even a non-lucid one) can indeed help solidify knowledge and improve skills.

Good luck with the experiment. It would be cool to have it in the research section.