I'm running Oregon G6 Gator blades on my Woods PRD7200, they have a "fusion" coating that stays sharp much longer than the OEM blades. Looks like your mower has swing-away blades and I didn't see an offering on the Oregon web site for the 29186 Woods part number.
With the blades lasting 3 weeks, is this heavy commercial use or "home owner" use, how many hours of actual use?
If it is home owner use, a few suggestions for longer blade life:
Consider adding the front anti scalp roller if you have uneven terrain and keep getting in in the dirt.
Realize this is a finish mower and not a rough cut mower (if you are using it to rough cut)
Raise the cutting height to get above the rocks, or whatever you are hitting besides grass.
Remove obstacles mentioned above from mowing area.
I sharpen the OEM blades on my Woods about every 10 hours of use and the Oregon blades 15 to 20.