Father bought one of these years ago .. after many years and leaking "Scent" onto the floor it's made a mess but killed nothing.
Fen Traps work and are much much much cheaper.
There was a youtube video about someone who had issues on first using one, then he removed all traces of the proprietary attractant, made up his own concoction - and it worked far better, I am trying to find it again to see what he did...
I sometimes wonder if vermin become used to the scent of proprietary attractants hence thing seem to be ineffective?