Never…ever…put DIY in a report. Even if you explain with exquisite detail how to fix it (anything), you now own it if the client screws up the fix. And the “fix” may become more complicated as a pro works on it.
My two cents…write up something like “Water intrusion through foundation wall. Recommend evaluation and correction by a professional foundation contractor.”
With something like that, you have done your job as a home inspector who is acting as a generalist observer. Describing the repair is beyond what we do.
As often mentioned in other threads on this forum, it is OK to advise your client that these kind of repairs are always best done from the outside.
I understand and that’s cool. To your question, foundation sealing should nearly always, be done from the outside in addition to providing good positive drainage of surface water away from the foundation to at least 5’ and 10’ if there is room. In areas where the soil is often near saturation, traditional surface drainage guidelines are less effective. In my area, a good drainage apron around a house, frequently solves these issues in all but the rainiest periods.
But the larger point of my response is for our newbies, who are here to learn (among the many things to learn) how to properly write a report.