Among your switches at Admin Panel -> Settings -> Switches you have a "timed reciprcocal verification" option. Here's what it does when activated:

1) When a reciprocal link is submitted, it's given 2 days. After 2 days a check is performed to determine if it's reciprocating. If it isn't, the link is unvalidated. If you don't manually validated it within 2 days it's deleted.
2) Every 30 days, another check is run. If the site fails this check a warning email is sent and it lands in the 48 hour pile. If the site still isn't complying after 2 days the link is unvalidated. If you don't manually validate it within 2 days it's deleted.

As you can see, this saves you enforcement time at the cost of possibly deleting sites for innocent mistakes.

You can change 2 days to another number of days at Admin Panel -> Listings -> Link Settings -> Reciprocal Verification Timings.

A recipcheckdays tweak is available to change it from checking every 30 days to checking every some other number of days.