Looking at the challenge definition and solution codes gives me flashbacks of the Censor Dispenser challenge project.
Ah yeah that looks like quite an interesting challenge, not seen that before. It is sort of our intermediate case where we want to do just one round of replacement (except that ours is slightly harder as it can be in the middle of a word).
Any other solutions or thoughts on my solution?
Your solution is quite impressive. Mine is still a work in progress. Unfortunately, my wheels of progress turn very slowly.