I did a google search on it, $300 for some fittings and some tubing? I guarantee it doesn't get all the water out.
Ask the company if they offer a guarantee.
I think it's worth your time to completely drain it, and refill when you use it.
Have you drained your own block before? Have you ever had to use a wire or screwdriver to clear the silt log out? IMO I would not trust a small line system.
Allot of money to do the same thing we do with wrenches and a screwdriver.