Well, help is on hand. I bet you have an old pen that has dried out. As long as it is one that you can take apart, then this should be easy.
This is the type I used. Everything comes apart from the front end.
It's a cheap one, so no need to spend a fortune or use your best pen. Next step is to take it apart, like this
Get a piece of thin wire, put the plug in a sink ( you don't want to lose the nib) and run some warm water. Now use the wire in the nib and down the tube to get rid of the rest of the ink. Run it under the tap. Get it as clean as you can, and shake it out onto a rag to dry it all out.
Now here comes the fun bit. IF you have got it clean enough, you can use it like a straw to suck up some food grade glycerine. If not, or you don't feel happy doing that, get a small syringe with its needle to draw up the glycerine and then release it into the tube. Keep your finger over one end to keep the suction, until you reassemble the pen. You are now free to scribble away, dust with embossing powder as normal and heat. If feeling really clever, there is no reason why you shouldn't mix up your favourite coloured ink with glycerine and use that. Minute quantities of both are all that is needed.
I strongly suspect that you could do pretty much the same with a used up felt tip, only you could use a dropper or syringe to get the glycerine into the filling.
I don't know about you, but in the past I have thrown away virtually unused Sakura pens because I could not get them to write.
I had tried warming them, running under a warm tap, soaking, you name it and nothing had worked. Anyhow, I decided to give something else a go and see what happened. A few days ago I had taken a normal ballpoint pen to bits and filled it with glycerine to make an embossing pen. Works great. One of the things I did to clean out the tube was stick a thin wire into it.
Well, With the Sakura pen, I thought I'd probably find the ink in the tube bunged up but it wasn't, in fact I lost the ink on taking off the nib, simply because it hadn't occurred to me that it would run out. Still, nothing was coming out of the nib so I thought I'd give that the same treatment. I stuck the wire in the hole and wiggled it around for a few minutes before washing it under the tap. Still no go, so I did it again. This time, the last of the old ink flowed through the nib (still without the tube on it) so I knew it was working.
Can't have an old pen go to waste, so I put a couple of drops of black liquid watercolour, a drop of alcohol and a few drops of glycerine in a shot glass and mixed it with a cocktail stick. I use a syringe to slowly drop it into the tube, sitting it in some modelling clay to give me both hands free. Do this slowly or it will spurt out. (Do you see that black splodge?) Stick a finger over the top of the tube, take it out of the clay and re insert the nib.
I now have a black embossing pen to go with my clear one!
Assuming you don't do what I did and lose all the ink, you should be able to just get your pen working again, if you don't want to re fill it.