Hate to admit it but I’m a #1 Follow the Instructions normally for a newer or expensive (aka valuable) kit. Thrashing an older obsolete kit, seems to become full bore #4 Helter-Skelter.
Productive hobby shop run. C-channel plus, MCLT plus a product new to me, Mr Retarder…lol!
With a name like that how could I not buy it!
Anyway, it’s supposed to be “slow-mo” for brush painting Mr Color & similar paints. Naturally, the warning label is priced over. Warning 
parts thst are visible look extremely serious so probably join to research before using it.
Used a paint brush handle & sand paper on the C-channel.
Plus sanding, adding a back strip and coat of thinned Tamiya Basic Gray/Molak Stucco Putty.
Off to a slow & ugly re-start but finally working on the old Gunzy kit again!