I've recently started using policyd-weight, which nicely handles this sort of case (and mostly mitigates the impact of single bofh rbl mis-listings.) It performs basic sanity checks on incoming connections but still works OK with dynamic IPs (and other non-matching reverse lookups) unless you are listed in multiple RBLs.

It trimmed my inbound spam volume ~90% (reducing the load on my dspam filter accordingly.) If you're a postfix user, check it out http://www.policyd-weight.org/