Brewed up a pilsner about 4 weeks ago. I was going to transfer to 2ndary after two weeks, but the airlock was firing once every 7-10 secs. Finally, shortly after the end of the third week, the airlock slowed down to once every 20 sec so I transfered to the 2ndary. Now it is firing once every 30-40 secs. No, I have not checked the final gravity--soot..l.you lose so much potential beer just transfering...I didn't want to lose more with a sample.
You need to wait until it stops, I'm afraid. What temperature are you fermenting at? Cooler temps mean slower ferments. Also what was the OG? Bigger beers take longer for sure, although if it's a standard pil, I don't imagine that's the case. If you are unwilling to take a gravity reading, you must wait. Sometimes they take a while, relax...
Once the wind has been broken, it cannot be fixed.
Oftentimes a diacetyl rest has the nice side effect of speeding things up and getting rid of all the remaining fermentable sugars.
German home brewers often do a force ferment test for their lagers. This way they know what the FG will be and they know how far way they are. This is especially helpful if the fermentation is just crawling along.