Ways to heat your engine?

Since there is no block heater has anyone tried a lower radiator hose heater (cut the hose and install there) or a circulating heater (cut the heater core hose and the lower radiator and the pump circulates the water). There is one other choice- the Vvkb Engine Block Heater Titan-P1 which you just cut the heater core hose and install as it is a enclosed pump and heater. Question- which heater hose is the inlet if you decide to install a circulating heater? Thanks.