Is it possible to get krend splashes off indian sandstone patio slabs

Definitely do not use brick acid. It's too strong for the sandstone or any stone and will result rust. It draws the iron on the stone out into rust.. So a big no no. Try to use soapy water and a stiff sponge or mix with a little bleach. Hope this helps

I would perhaps try using a pressure washer first, tackling the stained area at different angles. It that isn't effective I would reccomend using a 120g sanding disc on an angle grinder or drill and lightly buff the area. Avoid too much pressure of holding it directly in one place as this can result dents. Hope this helps

Depending on how much is covered I suggest replace the affected slabs be easier and finish product will look better