Anchor question for a drift boat

[loomisfun]

I am getting really close to having my boat in the water but I have a question on the anchor/anchor line. I have seen on some boats an "idler" pulley that is off of the anchor arm. Supposedly this will significantly reduse the felt weight of the anchor. I am installing a crank that will hold the line and pull the anchor up. It is rated for 18 lbs and my boat anchor will be between 30 and 35 lbs.

Has anyone here rigged their system with this "idler" and if so, can you explain to me how it is done?

Thanks,
Loomis