Thanks for the replies. My slowest board is the MS6119 and it is supposed to go down to 2x66 MHz, but I looked quickly and could not find jumpers 5-6 on the board which is strange. The board lacks some fan headers as well so it might be a non standard OEM version or something.
I also recently aquired a Epox bx3 which has very nice self explanatory jumpers, but it only goes down to 4x 66.
I read something here that if you run a very low clock you wont be able to use L2 or something like that. Maybe it makes the set up too slow.
But atm I neither have an unlocked P2 or a motherboard that can set multipliers. Finding a CPU is quite easy but the motherboard, I'm not even sure it exists. The ASUS P2B-S seems to be your best bet but it seems to have jumpers. It might be possible to connect a turbo switch to it I guess.
An alternative would be to go with a low multiplier Pentium 3 or something and just lower the fsb to 50 and get something like 200 mhz but I guess it is too fast to be useful.