We have a 12-year old red cedar home in central Virginia. During the Spring and Summer we have very high levels of humidity, dust and pollen. This combination leaves a thick layer of grime on the logs. We purchased the house nine years ago and begain treating the logs with Cetol products by Sikkens. How do we clean the logs on an annual basis? Is light power washing okay? I don’t want to strip the logs, just clean them. Thanks.