Effectiveness of granular Milky Spore compared to sponge/liquid?
I have been planning on an application of milky spore and now is just about the right time. I've had some massive grub damage (last year my lawn rolled up like a carpet and there were tons of white grubs when I dug into the soil), and would like to try the "organic" way first. I was all set on ordering from a biological supply company and buying the sponge that you squeeze into water and apply when I was renting a U-haul today and saw in the grub/fertilizer isle at a local ACE hardware a 20lb bag of milky spore that is sold in the consistency of a starter fertilizer. The bag says good for 7000sq ft. which would give me several years of applications (since I know it can take 2-3 years for maximum effectiveness).
The brand is made by St. Gabriel Laboratories and seems legit (0.2% spore concentration with the rest inert stuff for even spreading). It was about $40 which would be MUCH cheaper if I can get multiple uses out of it than the sponge/liquid version.
So my question is is this going to be as effective when watered in as the more expensive and less convenient sponge that I've read all about?
Thanks in advance for your help.