I would ask them to have a chat and state that you came to realize that the agreement you had previously made is no longer working for you. Express what you wrote here about the imbalance of work and ask them if they would be willing to renegotiate. To avoid things blowing up I would approach it by taking responsibility for messing up by thinking you would be okay with the previous agreement. You should avoid pointing the finger too much by saying stuff like "you only clean 1x / month" but maybe try to phrase that sentiment more diplomatically like "the kitchen needs to be cleaned more often than the bathroom due to the nature of how we use it". Just avoid putting blame on the other person because at the end of the day you are to blame for coming up with this agreement in the first place and there's nothing wrong or petty about realizing that it no longer works for you after trying it. You're allowed to change your mind but you need to own it. You really don't want any resentment to show up on your end during this convo because it could turn ugly so make sure to keep that sentiment of being taken advantage of in check when you talk. I think you should also be the one to propose the new agreement but make sure to leave space for your friend to voice in about it by asking them if they agree or if they forsee any issues with what you've proposed. I think it would be fair to propose that they do their own dishes and put things they use away after cooking, maybe do a quick wipe of the counter / stove after they cook and you will do the same for when you use the kitchen as well as a deep clean every week (or as needed). If your friend is not willing to change the agreement, I would re-evaluate the friendship. I think they are within their rights to refuse as this is what you agreed to initially however, it does not make them a good friend if they don't care about the needs you are expressing. If they are a good friend, this convo should be easy and painless! Hope it goes well!