In New Zealand they use Kiwi as a tenderizer for squid. Soak for at least 60 minutes but not more then 90 or the kiwi will transfer flavor to the squid.
I make a sauce out of figs, sugar, lemon zest and water (sometimes a bit of lime juice) that I use on pork tenderloins and it gets pretty high marks from guests.
I tried and did not like fig tea I ordered from Lebanon so I tried soaking some really tough cuts from an old buck and it had varying degrees of success.