I've yet to do a wet clean on my X-T1 sensor. Normally, just a Giotto rocket blower takes care of it. However, if you changed lenses at the shore, it could be some fine mist/sea spray got in there as it's being blown about by the wind. I'm assuming you used F22 to test the cleanliness? Unless you regularly shoot at that aperture, and the spots are just a few that can be seen when closed down that much, I wouldn't worry about it. Unless the place you had the sensor cleaned before would do you a solid and clean it again for free.
Honestly I try NEVER to change lenses at the beach/sandy area. No matter if there is no wind or not, there are still particles in the air.
MikeD66 reacted to jlmphotos in XT-1 sensor and dust