You can always fake a longer animation with more than 10 frames using any framerate. However it requires some clever entity work.
Here's an example i've just put together using 3 frames:
1. Make the textures (the frames).
2. For each frame, create a func_wall_toggle brush and apply each texture to one of its faces. Then name them:
1st frame: fwt_frame1
2nd frame: fwt_frame2
3rd frame: fwt_frame3
3. The func_wall_toggle that has the first frame applied to it should start visible. The other frames should start invisible. You can do this on the Flags tab by checking the Start invisible checkbox
4. Place the following point entities:
1 multimanager
6 trigger_relay's
5. Open the multimanager property window. Name the multimanager:
mm_anim_cntrlr
6. With SmartEdit off, add the following keyvalues:
Key: tr_frame1_2
Value: 0
Key: tr_frame2_3
Value: 0.5
Key: tr_frame3_1
Value: 1
Key: mm_anim_cntrlr
Value: 1.5
The values here represent the actual framerate, in this case, 1 frame every half a second.
Finally, set the multithreaded flag.
7. Now for the trigger_relays. Here's an image to help you identify them:
1a
Name: tr_frame1_2
Target: fwt_frame1
Trigger State: Off
1b
Name: tr_frame1_2
Target: fwt_frame2
Trigger State: On
2a
Name: tr_frame2_3
Target: fwt_frame2
Trigger State: Off
2b
Name: tr_frame2_3
Target: fwt_frame3
Trigger State: On
3a
Name: tr_frame3_1
Target: fwt_frame3
Trigger State: Off
3b
Name: tr_frame3_1
Target: fwt_frame1
Trigger State: On
And thats all. All you need to do is trigger the multimanager.
Note that this example uses 3 frame. More frames equal more entities (more trigger_relays).