I used the diamond spray on the felt pad that comes with the SRD modular paddle strop recently to achieve a better edge on my Wacker and my TI. It worked like a charm on both str8 razors.

Don't apply the diamond spray too heavily, though. Additionally, you only need to strop the razor on the sprayed felt 10-15 times. See if that works. If not, then perhaps 5 more.

I hear that chromium oxide is good too, although I haven't tried that method yet.

Just my 2 cents.