In the Debug Options screen (System Configuration > Logging Options > System Log Files > Debug Options) there is an option to flush the OCSPD cache. This option is intended to be used when troubleshooting or testing.

When using OCSP to verify client certificates, OCSPD caches the responses it gets from the OCSP server. The OCSPD log messages appear in the system messages log. This cache can be flushed by pressing the Flush Cache button. Flushing the OCSPD cache can be useful when testing, or when the Certificate Revocation List (CRL) has been updated.