I took a cake decorating class years ago. I know you can buy a screw on cap for inserting into a pastery bag. You could find a plastic bottle the right size and screw the cap onto it. Then use the decorating tips, they come in all sizes and would be easy to clean.
I ordered a syringe with a long bent tip: monoject-412.
http://www.amazon.com/s/?ie=UTF8&keywords=monoject+412&tag=mh0b-20&index=aps&hvadid=1321079965&ref=pd_sl_88qcjt4ep 6_e
it works great for giving meds to my dogs also.