You can spray it down with a hose just don't direct a strong stream at a bearing. I wet my bike down to remove the mud and much as possible and the use soap and a rag to wipe the film off the frame. For the dirt around the bearing like the BB and wheels I use a paper towel or a rag. I had more problems with ridding a rail trail with fine lime stone dust getting into my bearings then anything else. For mud I would do the same thing. The chain will suffer the most in muddy conditions so don't oil a dirty chain. Brush and clean the chain before lubricating.
