I don't think drips matter ; for virus transmission there has to be some way of cell contents (virused) to get into the other cell contents directly.
I sterilise my cutting tools with a little blow-torch - the one I also use in the kitchen making creme brulee .
But sap sucking insects are the normal vector,especially ones which flit about from one plant to another, so keeping the pests down is important.
I agree about disposing of virused plants - tied up in a black plastic bag for the incinerator.
But the problem is those where "maybe its virused..." Isolation is the ideal, but not easy.