I use the stone weights I got from the bottom of my plant bunches.
Cut a little hole in the bottom juicy bit of the cucumber, thread some cotton through, tie through the hole in the weight.
Voila.
All my fish eat it, the Angels, Cory's, Pleco's and especially the Ruby Shark!
I mostly have it in there because of the shark and noticed a big difference between putting cucumber in there to it eating my other plants.
Couple of times a week, leave it 24 hours. Remove skin and if there's any wastage.