Ok, here's what I do:

Get a 16 oz thing of Oj- Preferably pulpless. Also get yourself a cup or something you don't want to keep, or an ice-cube tray if you have multiple different seeds.

Put some Oj into the cup or tray and toss the seeds in. (mark the tray somehow so you don't forget)

Let 'em sit in there un-refrigerated for 3 to 5 days soaking. Some mold will prolly grow ontop of the Oj, don't worry about it.

When they're done soakin', peel the mold off carefully- there'll prolly be several seeds stuck to the underside of it. Pick 'em out. Suck out the rest of the Oj somehow- I use an old syringe, or if you just have 1 kind in a cup just carefully pour it out.

Plant the seeds & keep 'em warm- I like those "seedling heat mats" as they seem to work well. I generally don't bother with the "dome" thingy that comes with "seed starting kits" as it seems to keep in too much moisture- I've found the seeds seem to sprout *just* before the medium dries out all the way, for some reason. So yes, it can be a tedious balancing act.. Not too wet, but not too dry.

Using this method I've managed to sprout seeds 5+ years old- But yes just out of the fruit ones sprout *much* faster.

Rather than buying ebay ones- Where you can get rather jacked on the price (to be sure) you may want to try www.tradewindsfruit.com or see if you can entice some trades here on the exchanges side.