I've been thinking of using Lm more and have been formulating my process.
I was thinking of using my big, powerful wet vac connected to my power-brush to dry vacuum the carpet first.... then bonnet the carpet.
any stains needing extra attention would be heavily wetted with a pump up sprayer then extracted with the wet vac.
for stairs I would basically heavy vacuum then prespray/scrub, allow some dwell time, then the use the pump up sprayer to wet out the steps, then extract with the wet vac, then towel off.
this to me is the best possible method to 'LM' clean stairs