Mine have all stopped flowering. I have a couple dozen in a small area on
the allotment. Location exposed, 500'amsl and East facing.
I believe you are meant to lift them, trim the stems down to 6" and turned
upside-down for a length of time:-

1. How long to keep the exposed to the elements?

2. Would it pay me to wash any soil off first?

Here's the forecast for the SW for next couple of days.
http://www.metoffice.gov.uk/weather/...t_weather.html

They will be wrapped in crumpled newspaper and bagged in the loft.
Many thanks for your replies.
Bertie