First, moss is not the plague that many perceive it to be :-) Yes, it can be problematic on roofs or on shaded paving areas but otherwise its effects are predominately only aesthetic. And it can be a good indicator of other cultural issues that should be addressed first.

Moss in gravel and/or bark is no big deal. If you want to get rid of it, there are various methods, although heading directly into our low light, rainy season would not be my preferred timing! In our area, moss is a given and learning how to cope with it is far more satisfying than attempting to eliminate it.....which you can't. You are only delaying the inevitable.

Various moss control products contain ferrous sulfate, ferrous ammonium sulfate, zinc sulfate or ammoniated soap of fatty acids. All of them can kill moss but effectiveness is variable. The zinc products are probably the most effective but are typically recommended only for roofs and structures, as zinc can be toxic to plants. The ammoniated soap (MossOut) is the most environmentally safe but is also the least efficient.

Thanks for the response to my question, the preaching your beliefs on me not so much. If I was okay with the moss in my gravel and bark I wouldn't have posted the question.

Not trying to preach any beliefs -- only providing you with information. What you do with it is your concern. Just so that you realize that treating for moss in our climate is going to be a ongoing and repetitive battle. Most folks opt for a less labor-intensive approach, but it is always your choice.

Time to add more gravel and bark. Some maintenance is required on almost any surface.
I like moss in most cases, but I guess you could rake the gravel and bark fairly often and get rid of some of it if you don't want to buy more materials or sprays.
Mike

Just a heads-up on the moss, I have limestone pavers edging my lawn next to a gravel patio area. Spreading moss-out works pretty well at killing the moss, but the iron granules rust on the limestone, so if you're concerned with getting rust spots on anything nearby, be sure to spread while it's dry, sweep them off of what you don't want stained,and then water it in. I did this with my front lawn that touches concrete driveway fairly effectively a few years ago.

my asphalt driveway was getting very green this winter.
I tried full strength regular white vinegar on a patch during a dryish spell and was amazed to see it turn brown after several days.
so we sprayed the whole drive and all the moss is now light yellow and on the way to disappearing altogether.