Thank you so much for answering.
I definitely used the wrong term when I said I wanted the most "efficient" solution. I don't need at all computational efficiency, my dataset is not that large (I will need to change hopefully not more than a few hundred values in a data frame of ~10,000 observations with around 30 variables).
What I actually meant was I was looking that was efficient in terms of my management of the code... coding it in a way that will be flexible in the future when I need to add to the list of values to change.
Right now each change is a mutate command changing the specific value in the data frame. I would like to have a data structure for the observations that need a change, what variable has to be changed, and what value needs to be put in, so that each time I have to add to it I only need to add this required information to it and the process is already set up. I hope I am managing to explain myself.
The values will not always be numeric. The changes are being done to variables that are a mix of numeric, character, boolean and (maybe) dates.