Mortar Stains on Refractory Bricks

[Poops]

Hi All

So I'm about five courses high on my 40" (ish) dome including having completed the entry arch using refractory bricks http://www.fornobravo.com/forum/f44/...lia-15738.html (Materials in Adelaide South Australia) which are a creamy colour and homebrew mortar 3:1:1:1 sand, cement, lime and fireclay.
I have regrettably been somewhat slack in cleaning the excess mortar from the inside of the dome as it goes up. I've used a stiff brush to get the joints at least flush, but have some unslightly watery grey stains.

I'm looking for tips on how bext to clean this up. On normal red bricks I'd use some Hydrochloric acid, but wonder if this would be suitable with refractory bricks, and whether this would compromise the strength of the mortar?

Appreciate any feedback, or how others have approached this.

Thanks

[Les]

Muriatic acid will do the job. It's nasty stuff and given repeated applications, will probably compromise any brick. If it's just a stain on the inside - let it be.
JMO.

[Tscarborough]

It is an oven, not the facade on your house.

If you do feel the need, make sure that you get a 100% saturation on the brick before you apply a dilute muriatic acid solution.

[brickie in oz]

If the mortar is on the inside it will just flake off with the heat of the oven so dont worry about it.
By the time you have done the curing fires it will most likely be gone.