This spatula is a close to ideal tool for getting product out of the bottom of a blender jar. (Edit: Other colors may be cheaper. Check out other colors if you're looking to save a couple bucks.)
Blenders in general aren't that great for processing hard solids into pastes without added steps (like soaking nuts or what have you). The ChefSteps pistachio butter starts out using a Vitamix to turn pistashios and sugar into a powder, but they move that mixture to a conche to reduce the particle size to a smooth paste. Making something that smooth would be impossible in a blender. Getting smooth hummus shouldn't be a problem; smooth pistachio paste -- not so much.