The section in the wiki is pretty straightforward. Most of Netgear routers have a rather similar TFTP recovery flash procedure.
(Similar advice for R7800: Netgear R7800 exploration (IPQ8065, QCA9984) - #5 by hnyman )
Just for triggering the recovery flash mode during the early boot process:
Sounds like you have not been able to make the device to enter the TFTP recovery flash mode. The advice in wiki for WNR2200 sounds a bit peculiar, as usually you need to release the reset button while the power LED still blinks.
You may need help from somebody who actually has WNR2200 to figure out the exact moment.