Those foam blocks work really well. You can measure to ensure you get the scarf blocked straight. What type of yarn did you use to knit the scarf? That will determine the best blocking method.

It is at bulky chunky weight. I can't find the information about it now, but it is a blend, bought in a craft store not a fine yarn.

If it is a blend that is mostly acrylic, blocking will do you little good. Acrylic doesn't block like a natural fiber would. However, you can steam block even 100% acrylic to improve the drape of the fabric. To steam block, place a slightly damp towel under the portion you are blocking and another towel on top, set your iron on high steam and steam the heck out of it, one piece at a time until it is all done. This method does not do much to set the exact shape, just to improve drape.