I use hot, but use Virosol on first cleans and any upvc/ gutter cleans. Great stuff. I spray it neat onto my brush, scrub onto surface , bit of water to lather up, scrub, leave while doing up another section. Go back, scrub clean, spray off. Fan jets on the lighter Xtreme brushes make it easier on the shoulders , especially for gutter , soffit cleans.
I tried tfr, but didn’t rate it. Virosol all the way for me. Straightforward to use.