Damp Single skin wall

[Hunterlit]

We have an external wall in our kitchen that is very damp. I have measured the height of the wall both outside and inside, and the ground outside is roughly 300mm higher than inside. It is a single-skin brick wall. I'm going to hazard a guess and say that at some point, the ground outside has been raised and has bridged the DPC. My plans are:

1. Create a channel outside with a DPC membrane in the channel, lapped up to the wall and finished with gravel. My partner isn't keen on this idea.
2. Use Dryrods from inside, below the ground level outside.

Number 1 is my preferred method, and I'm a bit hesitant about using a liquid DPC because some people say they don't work. Also someone has repointed parts of the wall with sand and cement instead of lime, which I think may be causing issues; however, I don't believe it is causing as much of a problem as the ground level being raised.