This year I needed some rootstock for grafting, and happened to be near enough Exotica to grab some rootstocks.
They sell small seedlings for pretty cheap, around 10 dollars.
When grafting, I noticed a few of them had pretty interesting sap smells, some had strong indochinese aromas (like a parsnip), others had strong citrus aromas. One in particular had a orange/vanilla smell, the graft failed, so I will grow this one out.
If you have space and want to gamble Gary Zill style, you might try crushing some leaves the next time you are at exotica, and picking some seedlings to try out.