You could choose hydrate 80 or jenolite. Jenolite is good, so you might want to save your money, and save even more by going to Dynax for the underbods, and S50 for cavities. Dynax and S50 are available 750ml spray cans, so it's easy as lanoguard to apply, and if yu were using one of those hand sprayers, it doesn't dribble over your hands so much. 3 cans of jenolite should go a long way. Some people won't put any coating over it, and just retreat the necessary bits each year. I think you might need to rinse with alkali solution to neutralise the acid, but a chemist could give better advice.

Do you use a trolley jack for lifting?

I might give dynax a go then over the top of my jenolite if it’s that easy to apply and a bit cheaper than hydrate 80. How does s50 work then and where would I generally use it you mean inside of cills and arches?