How big is your wax apple and how long has it been in a pot or in the ground? I don't know much about wax apples but have several friends that grow it. Once they get established, they can be prolific producers but some varieties have bumper crops followed by 1-2 years of less fruit. Allowing smaller trees to hold fruit will prolong the period it requires for the tree to get established.
Here is a great thread on foliar feeding.
http://tropicalfruitforum.com/index.php?topic=241.0I have used that fertilizer or something very similar and I did a soil drench and foliar with it. I use about 1/2-1/4 of the recommended dose but I fertilize 2-4 times more frequently.
You also need to consider the timing of your fertilizer applications. I believe most the wax apples around San Diego have already bloomed and matured their first crop with some later fruiting varieties still producing some blooms.
If your tree is aready large and fully established, try reducing the amount of Nitrogen given to your tree and give your tree some drought stress prior to expected blooms. In early Spring, give it some organic 0-10-10 so that it will slowly release its nutrients.
Simon