Experimenting ways to stop their urine marking

When I came home last night, they greeted me with this - stray pee again!

I have to clean up twice a day - morning before work and evening after work. It's really energy exhausting for me. The stray pee was semi-wet and cold which might indicate it was done at least an hour ago. 

Recently I am cleaning their stray pee with the diluted vinegar (1 part white vinegar in 2 parts water). But I do not like the acetic acid odor so I added a few drops of Lavender oil. No, Lavendar oil does not calm them much.

So i anticipated that they would stray pee  like the day before, outside at their playpen since I free roam them at night. I sprayed (neubulized spray) the diluted vinegar without cleaning dry outside their playpen before I went to sleep. Then this morning, guess where they stray peed?

Yes, within their playpen! Hahahahaha but I still have to clean up >:(   So this morning, I decided to spray the vinegar around their playpen before going to work. I think Koogle don't like the acetic acid smell and rested on their litter tray instead! 

I hope the diluted vinegar will work to curb them from stray peeing.

At evening when I came home, darn! they stray peed again. 

I'm not sure if I have sprayed those areas this morning. Hmmmmm ok, I shall try tonight to spray bigger areas. If spraying diluted vinegar without cleaning dry works, then all these days of bonding effort really worth it! 

Now I shall pray and wait. :D 

Before I turn in for the night....they posed so close to each other but again, for less than 5mins. 

Update: 23 July 2014 morning before work.....

Stray pee spotted outside of playpen but on the area where the diluted vinegar not sprayed on. Argh!!! I think I need to mop my whole floor with diluted vinegar soon to stop them from any potential marking chances.