I use the Garden Safe Insecticidal Soap too ... it can usually be found at Home Depot and Walmart:
http://www.homedepot.com/p/Gar...
MJ,
oh my, your Hoya patella is so beautiful! I had a small H. patella at one time but gave it away along with some others when I was downsizing. Once we move and get settled I can really see myself getting back into Hoyas!