Kettlercise / kettlebells

You could log the amount of minutes in Cardiovascular under "circuit training, general" to get an estimate of the Calories burned.
Many MFP users choose to log or eat back only a percentage of the estimated exercise Calories burned per minute that are provided by the MFP Exercise Database, because the estimated Calories burned are based on metabolic equivalents for tasks (METs) for the general population of the same body weight. The Exercise Database may provide a higher estimated amount of Calories burned per minute than is actually burned for a user's particular situation, because of the number of variables in performing an exercise, such as intensity levels.

There is only one "Strength training (weight lifting, weight training)" entry that can be added under Cardiovascular that will give a user Calories burned per minute.