Some old p30download files use RAR 2.9 or 3.x. Modern WinRAR/7-Zip might mis-handle the password encoding (especially with Persian characters).
It is likely a misremembered or clickbaity addition. Some users report that in 2016, one popular uploader used hot as a password for a series of game cracks, but that is no longer active. p30downloadcom rar password hot