The way to get rid of them is to spawn a hostile ship to destroy them, the functionality to remove them 'the easy way' hasn't been implemented in C#.
I prefer to keep using stations with 1.0 sensors. In the end, they are commercial and can stay forever then when I don't need them I just destroy the fleet with a click.
They are cheap. 121 tons and 7 crew also you can build from factories, fighter factories or shipyards and if you set low priority assignment you may not even lose a commander if enemies blow it up. You can go cheaper with smaller sensors obviously.
Active Buoy class Sensor Platform 121 tons 7 Crew 29.1 BP TCS 2 TH 0 EM 0
1 km/s No Armour Shields 0-0 HTK 2 Sensors 0/0/0/0 DCR 1 PPV 0
MSP 151 Max Repair 16.0 MSP
Lieutenant Commander Control Rating 1
Intended Deployment Time: 3 months
Active Search Sensor AS29-R100 (1) GPS 1600 Range 29.6m km Resolution 100
This design is classed as a Commercial Vessel for maintenance purposes
This design is classed as a Space Station for construction purposes
This design is classed as a Space Station for auto-assignment purposes
If I need long range I still use Buoys and Waypoints with fuel so that they dissipate after running out of gas. Eventually, the Small Boat bay is 500 RP and easy to research with the bigger one at 1000 RP.
To have buoys up and running you need to spend more between launchers, research the buoy and all relative techs. Also, a buoy of the same power will have to be size 33MSP and the box launcher alone is going to weigh the same as your hangar bay that can be used also to load fighters. If you go for a 0.3 launcher instead then you can still have 2 buoys in the hangar to compensate partially for the extra ammo able to be launched. However the launcher alone is double the size of the hangar and you will require a magazine anyway, again this makes it generally more tech consuming and less space-efficient.
Missile Size: 32.8 MSP (82.00 Tons) Warhead: 0 Radiation Damage: 0 Manoeuvre Rating: 10
Speed: 0 km/s Fuel: 0 Flight Time: 1 seconds Range: 0 km
Active Sensor Strength: 16 EM Sensitivity Modifier: 8
Resolution: 100 Maximum Range vs 5000 ton object (or larger): 29,627,582 km
Cost Per Missile: 25.6 Development Cost: 2,560
Chance to Hit: 1k km/s 0% 3k km/s 0% 5k km/s 0% 10k km/s 0%
Materials Required
Boronide 9.6
Uridium 16
Bottom line, considering it is not possible currently to clean the map, I think I am better off with this solution and considering costs I may keep using it even later as the only buoy aspect I was interested were mines and these should have been definitely sorted in 2.0 as they are still dodgy at 1.13.
Ultimately, if I decide to update them I can pick up the old while dropping the new. Once finished I can go back and scrap the one I don't need and recover material, MSP and more. Buoys won't allow you to do that.
Disclaimer: All the above are at average Ion techs (no techs above 10,000 RP) which is when you probably starting to explore the galaxy a bit more.