In order to get the very best sound and response quality you should remove any remaining rosin from the string. During breaks in playing, we recommend that you wipe off any remaining rosin from the string with a soft cloth.
After playing on a weekly basis, make sure to clean the string with the Pirastro string cleaner. This liquid contains alcohol and in no circumstances should it come into contact with the varnish of your instrument.
Wipe a little on the strings and they will be good as new!