downgrade from 10gR2 to 9iR2

 I have question about downgrade step/strategy. 

We have database with version 9.2.0.4 and planning to upgrade to 
10.2.0.4. I know that we can directly upgrade 9.2.0.4 -> 10.2.0.4 

Now in case if we have to downgrade database from 10.2.0.4 back to 
original version which is 9.2.0.4 which is not supported way as per 
metalink docid: 398372.1 we need min. 9.2.0.6 or higher !! 

My question is can we downgrade from 10.2.0.4 -> 9.2.0.8 even though 
we upgraded from 9.2.0.4 -> 10.2.0.4? Is this method is supported by 
Oracle? 

Or we need to upgrade first by 9.2.0.4 -> 9.2.0.8 then 10.2.0.4 so in 
case of downgrade we can rollback to 9.2.0.8? 

Please reply ASAP. 

Thx, 

Umesh