I remember a CFI who used to swear by a good broom as a deicer, he spun in after take off at Edinburgh."
Spot on llan - If you can afford avgas and the cost of flying then you can afford to use an approved deicer.
Anything else is not only a false economy but also potentially dangerous.
In the last 12 months I have used less than 20 litres of aeroshell 07 as an in flight deicing TKS fluid - it is very pricey but works very well at melting all the nasty rapidly accumulating white stuff off the windscreen, prop and the leading edges esp when I cross a front.
My aircraft has never required external deicing as it rarely sits outside rotting (in the winter I stick it in a hangar even when away from base if I am spending the night away)- The aeroshell costs me approx £1 per flying hour extra per annum to use and I don't begrudge it.
Why not put the aircraft inside a hangar if you plan an early departure the next day?
SB