You need to take the pebbledash off and inject damproofing into the bricks under pressure. You also need to do this inside after taking off the plaster. You can hire the machine to do the injecting and a drill to drill two holes into each brick.
It's messy but not too difficult. Afterwards you have to replace the pebbledashing with a skirt along the bottom to throw rainwater away just above your new damp course.
I would be very sceptical about anything that is supposed to cure damp by spraying the pebbledash.
On a more optimistic note, are you sure that it's not a simple case of the existing damp course being bridged by soil or a patio laid over it? If that is the case, simply remove whatever is bridging it and you may have solved the problem.
The solution you have given is for rising damp not penetrating damp, penetrating damp is caused by water getting into the cavity and penetrating the interior wall, there are several causes for this happening, my advice is to get someone in to look at it who knows what they are talking about.
As someone said above Beneck are very good.