Best rust solver/ converter ?

[Eric Bartels <bartels@maths.ox.ac.uk>]

In a recent message someone statet his opinion about Locktite's "Extend"
rust converter/primer. I was thinking of using another prdouct "Kurust"
(spelling?) to temporary stop some rust spots on my Midget (before I can
have them properly treated). Now I am wondering if someone on the list 
has had any experience with Kurust or can recommend any other product ?

Thanks,

Eric