Which weapons does the author allow for this method?

Only cutting melee weapons. The advice is to take on a Scrake with a bladed weapon and no guns.

Yes, solo or in multiplayer. Multiplayer is preferred because teammates can handle smaller ZEDs and heal you if you make a mistake.

Tactics

KF2 Scrake Tips: Berserker Blocking in Open Space

This is a short Early Access tip sheet from a 24th Panzer community player, built around a video of fighting a Scrake as a Berserker on Hell on Earth, using a perk-leveling map as the test arena. The method relies on blocking and parrying, and it was demonstrated off-perk as well.

Core advice

Pick open ground. Fight the Scrake in an open space with room to move.
Use a cutting melee weapon only. The author says to take it on with a bladed weapon, no guns.
Solo or team. It works in both. A team is better because others can clear smaller ZEDs and heal you if the fight goes wrong.
Blocking and parrying are also useful against other ZEDs, but the method shown is specific to Scrakes.

FAQ

Which weapons does the author allow for this method?: Only cutting melee weapons. The advice is to take on a Scrake with a bladed weapon and no guns.
Does it work solo?: Yes, solo or in multiplayer. Multiplayer is preferred because teammates can handle smaller ZEDs and heal you if you make a mistake.