Shimano Used

Shimano Used
How does one “flush” and/or clean out Shimano STI shifters?

I have an older set of Shimano 105 STI shifters that haven’t been used in over seven years. The levers move, but there is no “click”, and the cables will not move enough to actuate the deraileurs. Any advice for silvent washing them?
Edited to add that the shifters are not attached to deraileurs. This was in a bike box and disassembled. There are no cable housings to contend with.

Before you do anything you need to put cables on. Without a cable and back pressure on them STIs tend to not click. They may be perfectly fine. You can just test mount them on a bar, install cables and have an assistant hold the cable housing while pulling on the inner cable while you shift. The shifters should work fine.

Shimano T-curve Tournament 2009