I would recommend Green Clear from SmartSeal. It is advisable to wait for a dry period, ideally the moss should be bone dry, so it has the highest chance of soaking up the moss remover. Then wait a few days or even weeks and it should die out and eventually with rain wash off. Be careful though as they first place the rain will wash the excess moss into will be the guttering. So if you have access you could remove some with a broom.
I am sure you are aware, but would stay clear from any pressure washing at all on roofs.
Green Clear is a brand name for sodium percarbonate, (aka sodium carbonate peroxide) which I had not heard of. It seems to be a non-chlorine bleach.
If you search for recent posts about moss you will a number recommending Patio Magic (which I have used) and Wet & Forget (which I have not). Both contain benzalkonium chloride (which goes by a variety of names) and is a very effective moss killer.
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local