You could.. but it would wash off after a little bit of time.. there is Waxoyl which is basically a combo of wax and oil (duh!) that'll make it stick longer.. roversnorth sells it, or you can make it, i believe its chainsaw oil and parrafin wax.
Nice thing about LRs is that they self-protect the undercarriage by leaking all over it!
1966 Series IIa "Olive"
2001 Discovery II
2006 LR3 HSE7
Past: 1994 Defender 90 #416, 2001 Discovery II